Projecting Computer Display
Problem: All I see is a blue or black screen. I hit source and it skips over computer one or two.
Reason: The computer is not being recognized; There may be a loose connection.
Solution: The pigtail is either not plugged inot your computer securely, or it is not plugged into the blue or black VGA cable.
In most cases the white pigtail will be taped securely to the VGA cable. Sometimes the pigtail becomes loose. Check that it is connected properly. This might involve removing the tape, and re-attaching it.
Problem: All I see is a galaxy-like background. I don't see my desktop items.
Reason: Mirroring is not turned on.
Solution: Go to System Preferences < Displays < Arrangement, check the box to Mirror display.